While the Flow Cytometry Laboratory functions as a core for the scientific mission of the laboratories located within the NIA Intramural Research Program in Baltimore, several investigators, laboratory groups, or projects accounts for a significant portion of FY2009 resources. Usage by the Laboratory of Immunology (LI;Taub, Weng, Sen) varies between 60-70% of sorting and 50-70% of non-sorting (analytical) capacities, focusing on human and animal (mouse) models of immune status, immunoregulation, immunosuppression, and their relation to development and aging. Other supported projects involve those from the Laboratory of Cardiovascular Sciences (LCS: Boheler, ES cells and cardiomyocte differentiation;Xiao, reporter gene expression), Laboratory of Genetics (LG: Ko, patterns of ES development), Laboratory of Neuroscience (LNS: Mattson, reporter gene expression in neural stem cells and neurogenesis), Laboratory of Clinical Investigation (Bernier), Laboratory of Molecular Gerontology (LMG: Gearhart, antibody diversity and somatic hypermuations), and Laboratory of Cellular and Molecular Biology (LCMB;multiparameter cell cycle analysis). While the lab does not require co authorship on all publications for which we generate data, the following list, in addition to the bibliography below, documents publications from the IRP that include contributions from our core for this reporting period. 1) Schurman SH, Hedayati M, Wang Z, Singh DK, Speina E, Zhang Y, Becker K, Macris M, Sung P, Wilson DM 3rd, Croteau DL, Bohr VA. (2009). Direct and indirect roles of RECQL4 in modulating base excision repair capacity. Hum Mol Genet. 18(18):3470-83. 2) Yu Q, Sharma A, Oh SY, Moon HG, Hossain MZ, Salay TM, Leeds KE, Du H, Wu B, Waterman ML, Zhu Z, Sen JM. (2009). T cell factor 1 initiates the T helper type 2 fate by inducing the transcription factor GATA-3 and repressing interferon-gamma. Nat Immunol. 10(9):992-9. 3) Xu M, Sharma A, Hossain MZ, Wiest DL, Sen JM. (2009). Sustained expression of pre-TCR induced beta-catenin in post-beta-selection thymocytes blocks T cell development. J Immunol. 182(2):759-65. 4) Xu M, Sharma A, Wiest DL, Sen JM. (2009). Pre-TCR-induced beta-catenin facilitates traversal through beta-selection.J Immunol. 182(2):751-8. 5) Ghosh MC, Collins GD, Vandanmagsar B, Patel K, Brill M, Carter A, Lustig A, Becker KG, Wood WW 3rd, Emeche CD, French AD, O'Connell MP, Xu M, Weeraratna AT, Taub DD. (2009). Activation of Wnt5A signaling is required for CXC chemokine ligand 12-mediated T-cell migration. Blood. 114(7):1366-73. 6) Lustig A, Carter A, Bertak D, Enika D, Vandanmagsar B, Wood W, Becker KG, Weeraratna AT, Taub DD. (2009) Transcriptome analysis of murine thymocytes reveals age-associated changes in thymic gene expression. Int J Med Sci. 6(1):51-64. 7) McNeill DR, Lam W, DeWeese TL, Cheng YC, Wilson DM 3rd. (2009). Impairment of APE1 function enhances cellular sensitivity to clinically relevant alkylators and antimetabolites. Mol Cancer Res. 7(6):897-906. 8) Dixit VD, Yang H, Cooper-Jenkins A, Giri BB, and Taub DD. (2009). Reduction of T-cell derived ghrelin enhances proinflammatory cytokine expression: implications for age-associated increases in inflammation. Blood 113:5202-5205. 9) Muniandy PA, Thapa D, Thazhathveetil AK, Liu S, Seidman MM. (2009). Repair of Laser-localized DNA Interstrand Cross-links in G1 Phase mammalian Cells. Journal of Biological Chemistry 284:27908-27917. 10) Ghosh MC, Baatar D, Collins G, Carter A, Indig F, Biragyn A, Taub DD. (2009) Dexamethasone augments CXCR4-mediated signaling in resting human T cells via the activation of the Src kinase Lck. Blood. 113:575-584. 11) Aggarwal M, Sommers JA, Morris C, Brosch RM Jr. (2010) Delineation of WRN helicase function with EXO1 in the replicational stress response. DNA Repair 9:765-776. 12) Liu J, Majumdar A,Liu J, Thompson LH, Seidman MM. (2010) . Sequence Conversion by Single Strand Oligonucleotide Donor via Non-homologoud End Joinng in Mammalian Cells. Journal of Biological Chemistry 285:23198-27207. 13) Nguyen H, Weng NP. (2010) IL-21 preferentially enhances IL-15-mediated homeostatic proliferation of human CD28+ CD8 memory T cells throughout the adult age span. J Leukocyte Biol. 87:43-49.